1. Field of the Invention
The present invention is related to dual, flush mounted antenna systems and, more particularly, towards dual antennas which are mounted in a piggyback fashion.
2. Description of the Prior Art
Antennas are generally designed to perform a desired electrical function, for example, transmitting or receiving signals of a required bandwidth, direction, polarization, gain, or other relevant characteristics. But mechanical constraints such as size, weight, location, and profile can under many circumstances be the most important criteria. Where a dual antenna system is required, especially in the missile systems, aircraft, and various projectiles, these parameters become all the more critical.
Several antenna dual antenna systems have been proposed. U.S. Pat. No. 3,818,490 to Henry Leahy discloses a dual frequency antenna array. The array has two repetitive radiator systems in a single aperture which operate in two distinct frequency ranges. The first radiator system is made up of a plurality of rows of a certain type of radiator element interspersed between which are rows of the second kind of radiator element. Robert Pierrot in U.S. Pat. No. 3,864,690 incorporates into a radome a dual antenna system by utilizing a dielectric whose thickness is transparent to a first frequency and a network of wires integrated with the dielectric designed to be transparent with a second frequency.
Both of these systems have various shortcomings because each antenna in a system is necessarily designed to operate in a distinct frequency range. This not only limits the electrical flexibility, but also affects the mechanical parameters. The inventor, by using the properties of parallel plate and microstrip radiators can, operate a dual antenna system in a piggyback fashion without deletorious electrical affects and with much mechanical savings.